Method of manufacturing a package carrier for enclosing at least one microelectronic element and method of manufacturing a diagnostic device

ABSTRACT

A package enclosing at least one microelectronic element ( 60 ) such as a sensor die and having electrically conductive connection pads ( 31 ) for electric connection of the package to another device is manufactured by providing a sacrificial carrier; applying an electrically conductive pattern ( 30 ) to one side of the carrier; bending the carrier in order to create a shape of the carrier in which the carrier has an elevated portion and recessed portions; forming a body member ( 45 ) on the carrier at the side where the electrically conductive pattern ( 30 ) is present; removing the sacrificial carrier; and placing a microelectronic element ( 60 ) in a recess ( 47 ) which has been created in the body member ( 45 ) at the position where the elevated portion of the carrier has been, and connecting the microelectronic element ( 60 ) to the electrically conductive pattern ( 30 ). Furthermore, a hole ( 41 ) is arranged in the package for providing access to a sensitive surface of the microelectronic element ( 60 ).

The present invention relates to a method of manufacturing a packagecarrier suitable for enclosing at least one microelectronic element andhaving electrically conductive pads for electric connection of thepackage carrier to another device. Also, the present invention relatesto a method of manufacturing a package enclosing at least onemicroelectronic element, which is based on the method of manufacturingthe package carrier, and a method of manufacturing a device which isapplicable for diagnostic purposes. Furthermore, the present inventionrelates to a package carrier suitable for enclosing at least onemicroelectronic element, a package comprising the package carrier and atleast one microelectronic element, and a device which is applicable fordiagnostic purposes.

Packages enclosing at least one microelectronic element are well-known,and various types of such packages have been developed. In general,dimensions of the packages are in the millimeter range. The packageshave various functions. Among other things, the packages serve forprotecting the microelectronic element and allowing for easy connectionof the microelectronic element to another device. The microelectronicelement may be a processor chip, a MEMS microphone, wherein MEMS standsfor Micro ElectroMechanical System, a transistor, a diode, a passivecomponent, a biosensor die, a chemical sensor die, etc.

In the field of packages for sensor dies, it is important that thepackage allows for controlled interaction between the enclosed die andthe external world. For example, in case the package encloses abiosensor die which is suitable to be operated for the purpose ofdetermining a property of a blood sample, the package needs to allow forcontact between the blood and a sensitive surface of the sensor die.

A package enclosing at least one microelectronic element and a method ofmanufacturing a diagnostic device are known from WO-A 2005/38911. Theknown package is an insulating plate with conductors on a first side,and a recess extending from the first to an opposite second side of theinsulating plate. The plate is suitably made by insert molding. Theconductors are therein provided on a sacrificial carrier, of which aportion is removed after the molding operation. A sensor die or chip isthen positioned on the first side so as to cover the recess, such thatit has one surface exposed in the recess. This surface is for instance asensor surface on which parts in a fluid to be analyzed can absorb.Channels may be defined on the second side of the plate so as to improvethe flow of fluid to the chip. This package has the advantage that thefluid processing is separated from the conductors.

It is a disadvantage of the known package that the provision of a recessextending through the plate is not easy or cheap, if the recess musthave a sufficiently small diameter so as to be covered by a chip. Such aconstruction requires a mould of very high quality, and thus of highprice. Moreover, the closing of a mould may not damage the sacrificialcarrier and/or any of the conductors thereon, while the conductors arepreferably designed near to an edge of the aperture.

It is therefore an objective to provide an improved method ofmanufacturing a package carrier suitable for enclosing at least onemicroelectronic element, which method is relatively simple but accurate,and which method allows for manufacturing arrays of package carriers byusing standard materials and processes, while offering a possibility ofmanufacturing a package carrier suitable for enclosing at least onesensor die. The objective is achieved by a manufacturing method whichcomprises the following steps:

-   -   providing a sacrificial carrier having a carrying surface and a        pattern of electrically conductive connection pads and        electrically conductive tracks at the carrying surface, further        having a covering member having at least one hole that is        positioned on the carrying surface, and covering at least part        of said pattern of pads and tracks;    -   bending the sacrificial carrier in order to create a shape of        the carrier in which the carrier has at least two portions which        are at a different level, such that the hole in the covering        member and a top portion of the covering member circumfering the        hole are present at a higher level;    -   forming a body member by applying material to the sacrificial        carrier, at the side where the electrically conductive pattern        is present, while leaving the top portion of the covering member        free; and    -   removing at least a portion of the sacrificial carrier,        therewith creating a recess with at least one electrically        conductive connection pad of the pattern suitable for        electrically coupling to a microelectronic element, which recess        extends to the hole in the covering member.

All steps of the method according to the present invention requirenothing more than an application of existing techniques. For example, aperson skilled in the art is familiar with the application of asacrificial carrier for the purpose of temporarily carrying a pattern ofelectrically conductive connection pads and electrically conductivetracks.

For sake of completeness, with respect to the sacrificial carrier, it isnoted that such a carrier often comprises a number of layers. Awell-known example is a carrier comprising two layers, namely a layer ofcopper and a layer of aluminum. In general, a sacrificial carrier servesfor temporarily carrying a pattern of electrically conductive padsand/or electrically conductive tracks which need to be applied to a bodymember. After the body member has been made, for example by overmoldingthe carrier at the side where the pattern is located, the carrier may bepartially or completely removed. In the process, a suitable techniquesuch as etching is applied.

A notable feature of the method according to the present invention isthat the sacrificial carrier is bent in order to create a shape of thecarrier in which the carrier has at least two portions which are at adifferent level. In this way, a simple solution is provided for theproblem of creating a recess for receiving a microelectronic element.When the body member is formed, the recess is automatically obtained asa result of the level difference of the carrier portions.

After the manufacture of the package carrier, a microelectronic elementmay be coupled to at least one electrically conductive connection pad ofthe pattern in the recess. This may be carried out by applying anysuitable connecting technique, for example soldering or ultrasonicbonding. When a so-called flip-chip bonding technique is applied, theactual connection is established in a following step, under theinfluence of heat, reflow or ultrasonic vibrations, for example. Thepositioning of the microelectronic element in the recess has theadvantage that the microelectronic element is moved towards another sidewithout making the body member very fragile. Moreover, due to thepositioning in the recess, the microelectronic element may beencapsulated afterwards.

The invention, moreover, relates to creating a hole having predetermineddimensions and a predetermined position at a bottom of the recess forreceiving the microelectronic element. According to the invention, acovering member having at least one hole is applied to the body member.The covering member may be patterned with a high resolution, byphotolithography, inkjet printing, screen printing or the like, so thatthe diameter of the recess/through-hole through the body member may bemuch smaller than in the prior art. Additionally, the covering memberprevents a direct interaction between a mould and the conductors, in thepreferred case of molding. Also, it is possible to position the holewith high accuracy, which is especially important in case an array ofpackages is manufactured. The covering member may for example be shapedlike a thin strip with a hole arranged at its center. A suitablematerial is an electrically non-conductive material, for example amaterial known as solder resist.

A practical way of forming the body member of the package carrierinvolves the application of a mould, wherein a space for receiving thematerial which is applied for forming the body member is created byputting the mould and the sacrificial carrier in a predeterminedposition with respect to each other. When a covering member having atleast one hole has been applied to the sacrificial carrier, the hole iskept open when the mould comprises a projection for preventing thematerial from covering at least a portion of the covering member, inparticular a portion where the at least one hole is present. Therefore,in such a case, the application of a mould having such a projection ispreferred.

In an advantageous embodiment, the projection of the mould is adapted toforming a trough-like recess in the body member, which extends from oneside of the body member to an opposite side of the body member. In thatcase, it is possible to create a trough-like recess in the body member,in such a way that the covering member having at least one hole is at abottom of the recess. In the package which is obtained as a result ofthe manufacturing method, this recess allows for an easy supply of fluidto the microelectronic element, through the hole.

The at least one hole which is created may be as shallow as possible. Incase a covering member having the at least one hole is applied, thecovering member may be as thin as possible. In this way, a package isobtained, in which a level of a sensitive surface of the microelectronicelement deviates just a little from a level of a surface along which afluid is conducted, so that a flow of the fluid is hardly disturbed bythe presence of the hole, and it is achieved that all of the fluid comesinto contact with the sensitive surface of the microelectronic element.Suitably, a trough-like recess is created in the body member. This maybe achieved with a mould having a projection.

In a particular way of carrying out the method according to the presentinvention, in case a mould is applied in the process of forming the bodymember, and a trough-like recess is formed in the body member by aprojection of the mould, during the step of positioning the mould andthe sacrificial carrier with respect to each other, a longitudinal axisof the projection of the mould is placed at right angles with respect toa longitudinal axis of a portion of the carrying surface of the carrierwhich is at a higher level than another portion. In this way, a packageis obtained which is robust, in spite of the presence of the relativelythin area where the at least one hole is present. In fact, thedimensions of this relatively thin area are limited to the dimensions ofan area in which bottoms of the recess for receiving the microelectronicelement and the trough-like recess cross.

Advantageously, in order to ensure a good protection of themicroelectronic element, the recess in the body member which is presentat a side where the removed portion of the sacrificial carrier has beenis closed after the microelectronic element has been put in place in therecess and has been connected to at least one electrically conductiveconnection pad. For example, the recess is filled with material, whereinthe microelectronic element gets encapsulated in the material.

When the package needs to enclose another microelectronic element, whichmay be completely enclosed by the body member of the package, a portionof the carrying surface of the sacrificial carrier, which is at a lowerlevel than another portion, may be applied for the purpose oftemporarily supporting such a microelectronic element, wherein theelement is connected to at least one electrically conductive connectionpad of the pattern which is present on the carrying surface. Theprocesses of putting the microelectronic element in place andestablishing the necessary electric connection are performed prior tothe process of forming the body member. After the body member has beenformed, the microelectronic device is embedded in the body member, anddoes no longer need to be supported by the sacrificial carrier.

The method according to the present invention is very well applicablefor the purpose of manufacturing an array of packages. In general,manufacturing an array of packages involves simultaneously manufacturinga number of packages, wherein the packages are arranged in rows andcolumns. When all packages are ready, the array is diced, so thatseparate packages are obtained. Advantageously, in case a package ismanufactured as a part of an array of packages, the sacrificial carrierwhich is used in the process of manufacturing the package is part of alarger sacrificial carrier which is bent in order to create a corrugatedshape of the sacrificial carrier. This is an easy way of creating ashape of the sacrificial carrier in which the carrier has at least twoportions which are at a different level, for all packages of the array.

The package manufacturing method according to the present invention,wherein at least one hole is created in the package for allowing for aninteraction between the enclosed microelectronic element and theexternal world, may be applied in a process of manufacturing a devicewhich is applicable for diagnostic purposes. In many cases, such aprocess further involves the step of applying at least one reagent tothe body of the package.

When the diagnostic device is operated, a fluid which needs to beexamined is put into contact with the reagent first, as a result ofwhich the fluid is put in a state which is needed in view of examinationby the microelectronic element. For example, certain molecules which arepresent in the fluid are labeled in a manner known per se, so that themicroelectronic element is capable of detecting the molecules.Subsequently, the fluid is put into contact with the sensitive surfaceof the microelectronic element, through the at least one hole.

Preferably, for the purpose of obtaining a controlled supply of fluid, amember which is adapted to conducting a fluid, in particular to puttingthe fluid in contact with the at least one reagent, and to conductingthe fluid toward at least one hole through which the microelectronicelement is accessible, is provided. When a trough-like recess is formedin the body member of the package, this recess may be used foraccommodating at least a part of the member which is adapted toconducting a fluid. For example, the member which is adapted toconducting a fluid may comprise a plate having a pattern of channels forconducting a fluid, which is present at one side of the plate. Also, themember which is adapted to conducting a fluid may comprise a bent hose,wherein the hose comprises a hole at the place where the hose is incontact with the package, in order to allow for the necessary contactbetween a fluid to be examined on the one hand and the reagent and thesensitive surface of the microelectronic element on the other hand.

The present invention will now be explained in greater detail withreference to the Figs., in which similar parts are indicated by the samereference signs, and in which:

FIGS. 1 a to 1 j illustrate subsequent steps of a process ofmanufacturing a package according to a first preferred embodiment of thepresent invention, wherein FIG. 1 a shows a bottom part of a mould whichis applied in the process;

FIGS. 2 a to 2 d illustrate subsequent steps of a process ofmanufacturing a diagnostic device comprising the package according tothe first preferred embodiment of the present invention, wherein FIG. 2b shows a portion of a hose which is applied in the process;

FIGS. 3 a to 3 f illustrate subsequent steps of a process ofmanufacturing a package according to a second preferred embodiment ofthe present invention; and

FIGS. 4 a to 4 i illustrate subsequent steps of a process ofmanufacturing a diagnostic device according to a second preferredembodiment of the present invention, wherein FIG. 4 i shows amicrofluidic plate which is applied in the process.

FIGS. 1 a to 1 j illustrate subsequent steps of a process ofmanufacturing a package according to a first preferred embodiment of thepresent invention. For sake of clarity, in the following, the packageaccording to the first preferred embodiment of the present inventionwill be referred to as first package.

In the process of manufacturing the first package, a mould comprisingtwo mould parts is applied. In FIG. 1 a, a bottom part 11 of the mouldis shown. The bottom part 11 of the mould comprises a plate 12 having anumber of elongated corrugations 13, which extend substantially parallelwith respect to each other, at a predetermined distance, and which arearranged on an upper surface 14 of the bottom part 11. In the shownexample, the corrugations 13 have a trapezoidal cross section.

In a first step of the process of manufacturing the first package, whichis illustrated by FIG. 1 b, a sacrificial carrier 20 is placed on thebottom part 11 of the mould. The carrier 20 comprises a sheet of amaterial which is to be removed at a later stage in the manufacturingprocess. For example, the carrier 20 comprises a sheet of copper. In theprocess of placing the carrier 20 on the bottom part 11 of the mould,the carrier 20 is bent, such that an under surface 21 of the carrier 20fits the upper surface 14 of the bottom part 11 of the mould, whereinthere is practically no space present between these two surfaces 14, 21.As a result, a corrugated shape of the carrier 20 is obtained, whereinthe carrier 20 comprises elevated portions 22 and recessed portions 23.

At an upper surface 24, the carrier 20 is provided with a pattern 30 ofelectrically conductive connection pads 31 and electrically conductivetracks 32. In the following, for sake of clarity, the upper surface 24of the carrier 20 is referred to as carrying surface 24.

In the example as shown in FIG. 1 b, the carrier 20 is used in a processof manufacturing an array of packages. Therefore, the carrier 20 asshown is provided with more than one electrically conductive pattern 30.In particular, in the shown example, three rows 33 of patterns 30 havebeen arranged on the carrying surface 24 of the carrier 20, wherein eachrow 33 comprises three patterns 30. Furthermore, a direction of the rows33 of patterns 30 substantially equals the direction of a longitudinalaxis 221 of the elevated portions 22 of the carrier 20, and a centralportion of the patterns 30 is located on the elevated portions 22. It isnoted that when the present invention is applied for the purpose ofmanufacturing an array of packages, the number of packages may be chosenfreely.

The central portions of the electrically conductive patterns 30 arecovered by a layer 40 of electrically insulating material, for example amaterial known as solder resist, which is an organic material such as anepoxy material or an acrylic material. At a central position, the layer40 is interrupted, such that a central hole 41 is obtained in the layer40. In the following, for sake of clarity, the layer 40 of electricallyinsulating material will be referred to as covering member 40.

After the carrier 20 has been placed on the bottom part 11 of the mould,a top part 15 of the mould is positioned above the carrier 20. In FIG. 1c, both the carrier 20 and the top part 15 of the mould are shown. Likethe bottom part 11 of the mould, the top part 15 of the mould comprisesa plate 16 having a number of elongated corrugations 17, which extendsubstantially parallel with respect to each other, at a predetermineddistance, and which are arranged on an under surface 18 of the top part15. In the shown example, the corrugations 17 have a trapezoidal crosssection.

The way in which the top part 15 of the mould is positioned with respectto the carrier 20 is illustrated by FIG. 1 d. A first notable aspect ofthe mutual position of the top part 15 of the mould and the carrier 20is that a longitudinal axis 171 of the corrugations 17 of the top partof the mould and the longitudinal axis 221 of the elevated portions 22of the carrier 20 extend at right angles with respect to each other. Asecond notable aspect of the mutual position of the top part 15 of themould and the carrier 20 is that the corrugations 17 of the top part ofthe mould contact the covering members 40 which are present on theelevated portions 22 of the carrier 20.

After the top part 15 of the mould has been put in the right positionwith respect to the carrier 20, a space 19 which is present between thecarrier 20 and the top part 15 of the mould is filled with a materiallike epoxy resin, for the purpose of forming a body member 45 of thepackages. In the process, any suitable technique may be applied, forexample injection molding. In FIG. 1 e, a filled condition of the space19 is illustrated.

In subsequent steps of the manufacturing method, the material of thebody member 45 is allowed to cure, and the top part 15 of the mould isremoved. The step of removing the top part 15 of the mould isillustrated by FIG. 1 f. At a side which is shown in FIG. 1 f, the bodymember 45 comprises trough-like recesses 46 in which top sides of thecovering members 40 are present.

After the body member 45 has been allowed to cure, there is no longer aneed for having a carrier 20 for supporting the covering members 40 andthe patterns 30 of electrically conductive connection pads 31 andelectrically conductive tracks 32. Therefore, the carrier 20 is removedby chemical etching, peeling, or another suitable technique. A top sideof the obtained array 50 of packages in the process of formation isshown in FIG. 1 f, whereas a bottom side of this array 50, which is aside of the array 50 where the carrier 20 has been, is shown in FIG. 1g. At the bottom side of the array 50, at the positions where theelevated portions 22 of the carrier 20 have been, through-like recesses47 have been formed, in which the central portions of the electricallyconductive patterns 30 are present, and in which major parts of thecovering members 40 are present, wherein the covering members 40 arearranged behind the patterns 30. Furthermore, as a result of the removalof the carrier 20, the holes 41 of the covering members 40 are open.

In FIGS. 1 h to 1 j, the next steps of the manufacturing method areshown in respect of a single package. However, it is just as wellpossible that these steps are performed on an array 50 of packages.Individual packages are obtained by dicing the array 50 of packages. Forsake of completeness, it is noted that each of the FIGS. 1 h to 1 jshows two different sides of the package in the process of formation.

The package in the process of formation, which is obtained after thesacrificial carrier 30 has been removed, and which is not yet equippedwith a microelectronic element, is also referred to as package carrier55. In FIG. 1 h, it is shown that an individual package carrier 55comprises a body member 45, a covering member 40, and a pattern 30 ofelectrically conductive connection pads 31 and electrically conductivetracks 32. In particular, at a side where the carrier 20 has been, whichwill be referred to as under side, a through-like recess 47 is present,which is covered by the covering member 40. Furthermore, at the underside of the package carrier 55, the pattern 30 of electricallyconductive connection pads 31 and electrically conductive tracks 32 ispresent. At another side of the package carrier 55, which will bereferred to as upper side, a trough-like recess 46 is present, and a topside of the covering member 40 is located at a bottom of this recess 46.Longitudinal axes 461, 471 of the recesses 46, 47 at the various sidesof the body member 45 are at right angles with respect to each other. Ata position where bottoms of the recesses 46, 47 cross, the packagecarrier 55 only comprises the covering member 40. As a consequence, atthis position, the package carrier 55 is relatively thin, and thepackage carrier 55 comprises a hole 41 which allows for access from theone recess 46 to the other recess 47.

In one of the final steps of the manufacturing method, which isillustrated by FIG. 1 i, a microelectronic element 60, for example asensor die, is placed in the recess 47 at the under side of the packagecarrier 55, at the location of the hole 41. Furthermore, themicroelectronic element 60 is connected to at least one of theconnection pads 31 which are present near the hole 41, by means of asuitable connecting technique such as soldering or ultrasonic bonding.

Subsequently, the recess 47 containing the microelectronic element 60 isclosed by filling the recess 47 with a suitable material such as epoxyresin. In the process, the microelectronic element 60 gets encapsulatedin a filler body 65 which is formed in this way. This step of closingthe recess 47, which is illustrated by FIG. 1 j, is the final step ofthe formation of the package 1. In case the package 1 is manufactured aspart of an array 50 of packages 1, and has not been separated from theother packages 1 yet, a process of dicing the array 50 is performed.

It is noted that in principle, the recess 47 does not necessarily needto be closed, but in many cases, it may be preferred to do so, for thepurpose of obtaining a good protection for the microelectronic element60.

In the first package 1 which is obtained as a result of themanufacturing process as described on the basis of FIGS. 1 a to 1 j, themicroelectronic element 60 is safely embedded in the filler body 65. Therecess 47 in which the microelectronic element 60 is located is obtainedin an easy manner, namely by bending a sacrificial carrier 20 in such away that a corrugated appearance of this carrier 20 is obtained. At thelocation of an elevated portion 22 which is formed in the carrier 20 inthis way, the recess 47 is automatically obtained when the carrier 20 iscovered by material for the purpose of forming a body member 45 of thepackage 1.

Although the microelectronic element 60 is embedded in the filler body65, it is still very easy to access the microelectronic element 60 in aproper manner. In the first place, the microelectronic element 60 iseasily connectable to another electronic device, through the tracks 32and connection pads 31 of the pattern 30, which are present at the underside of the body member 45, while extending outside of the recess 47,and which are directly connected to the microelectronic element 60. Inthe second place, a surface of the microelectronic element 60 isaccessible from the upper side of the body member 45, through the hole41. In case the microelectronic element 60 is a sensor die, this featureis very advantageous, as a sensitive surface of such a die may belocated right underneath the covering member 40, so that it isaccessible by fluids to be examined, etc., while the rest of the die issafely enclosed by the package 1.

An advantage of the perpendicular configuration of the recesses 46, 47is that an area where the package 1 only comprises the relatively thincovering member 40 is as small as possible. In this way, the package 1may still be as robust as possible.

It is noted that it is not necessary to apply a covering member 40. Inprinciple, the covering member 40 may be omitted, and the top part 15 ofthe mould may be adapted to the purpose of forming a relatively thinarea having at least one hole 41. However, when this way of forming thehole 41 and a surrounding area is carried out in practice, there is achance of the hole 41 getting obstructed by means of a thin layer ofmaterial which is used in the process of forming the body member 45, sothat extra actions, aimed at removing the thin layer, need to be taken.Also, it is more difficult to put the hole 41 exactly at a desiredposition, as this alternative way of creating the hole 41 is lessaccurate.

The first package 1 is suitable to be used as a part of a device whichis applicable for diagnostic purposes. A method of manufacturing such adevice 5, starting from the first package 1, is illustrated by FIGS. 2 ato 2 d.

In FIG. 2 a, the first package 1 is shown, wherein the recess 47containing the microelectronic element 60 is still open. In the recess46 at the upper side of the package 1, a member which is adapted toconducting a fluid is arranged. In the shown example, the member whichis adapted to conducting a fluid comprises a bent hose 70, whichcomprises a hole 71 at the place where the hose 70 is in contact withthe package 1, in order to allow for contact between a fluid to beexamined on the one hand and a sensitive surface of the microelectronicelement 60 on the other hand. A portion of the hose 70 is shown in FIG.2 b. The hole 71 in the hose 70 is simply obtained by cutting off aportion of the hose 70, at the position where the hose 70 is bent.

In FIG. 2 c, a further step of the manufacturing process of thediagnostic device 5 is illustrated. During this step, the recess 47 inwhich the microelectronic element 60 is located is closed. In yetanother step, which is illustrated by FIG. 2 d, the hose 70 is firmlyattached to the package 1 by means of a strap-like attaching member 78.By means of the attaching member 78, the hose 70 is fixed in a properposition and pressed against the package 1, so that fluid which isconducted by the hose 70 during operation of the diagnostic device 5does not leak away when it reaches the hole 71 in the hose 70.

When the diagnostic device 5 is operated, a fluid to be examined isconducted by the hose 70. In the process, the fluid contacts thesensitive surface of the microelectronic element 60 which is enclosed bythe package 1 of the diagnostic device 5, so that the microelectronicelement 60 is capable of measuring certain properties of the fluid.Output which is provided by the microelectronic element 60 and which isrepresentative of the properties of the fluid may be derived from thediagnostic device 5 in a most convenient manner, namely by connecting atleast one electronic device to at least one of the connection pads 31which are freely accessible at the under side of the package 1.

In the package 1, the microelectronic element 60 is positioned rightunderneath the hole 41, which is very shallow, as the covering member 40is very thin. An important advantage which is related to this feature ofthe package 1 is that during operation of the diagnostic device 5, theflow of fluid in the hose 70 is hardly hindered by the presence of thehole 41, and there is no risk of fluid staying behind in the hole 41, sothat there is no risk of the measuring results getting disturbed by anyof such unwanted effects.

FIGS. 3 a to 3 f illustrate subsequent steps of a process ofmanufacturing a package according to a second preferred embodiment ofthe present invention. For sake of clarity, in the following, thepackage according to the second preferred embodiment of the presentinvention will be referred to as second package.

In each of FIGS. 3 a to 3 f, both a perspective view of an under side ofthe package in the process of formation and a perspective view of anupper side of the package in the process of formation are shown. In thefollowing, the manufacturing process will be described for one package.Nevertheless, like the first package 1, the second package may bemanufactured as part of an array of packages.

In a first step of the process of manufacturing the second package,which is illustrated by FIG. 3 a, a sacrificial carrier 20 is provided.The carrier 20 comprises a sheet of material, for example copper. At acarrying surface 24, the carrier 20 is provided with a pattern 30 ofelectrically conductive connection pads 31 and electrically conductivetracks 32.

The carrier 20 is bent in such a way that two portions 22, 23 which arelocated at a different level are obtained. In particular, after bendingof the carrier 20 has taken place, an elevated portion 22 and a recessedportion 23 of the carrying surface 24 are discernible. At the elevatedportion 22 of the carrying surface 24 of the carrier 20, a coveringmember 40 is arranged in the form of a thin layer of electricallyinsulating material having a plurality of tiny holes 41.

In a second step of the process of manufacturing the second package,which is illustrated by FIG. 3 b, a processor chip 61 or anothersuitable microelectronic element is positioned on the recessed portion23 of the carrying surface 24, wherein an electric connection betweenthe processor chip 61 and the electrically conductive pattern 30 isrealized.

In a third step of the process of manufacturing the second package,which is illustrated by FIG. 3 c, the carrier 20 and the components 30,40, 61 arranged on its carrying surface 24 are overmolded with asuitable material, on the basis of which a body member 45 is formed onthe carrier 20, at the side of the carrying surface 24. In the process,the processor chip 61 gets encapsulated in the body member 45.

Preferably, the body member 45 of the package is formed by applying amould having a bottom part and a top part, like the mould which issuitable to be used in the process of manufacturing the first package 1,wherein the carrier 20 is placed on the bottom part of the mould. Thetop part of the mould which is suitable to be used in the process ofmanufacturing the second package comprises a pin-shaped projection. Whenthe package in the process of formation is positioned in the mould in aproper manner, an end of the pin-shaped projection contacts a portion ofthe covering member 40, so that this portion of the covering member 40does not get covered by material which is introduced in the mould forthe purpose of creating the body member 45. In stead, a recess 46 isobtained in the body member 45, wherein a top side of the coveringmember 40 is located at the bottom of the recess 46.

In a fourth step of the process of manufacturing the second package,which is illustrated by FIG. 3 d, the carrier 20 is removed by chemicaletching, peeling, or another suitable technique. The product that isobtained as the result of this step is also referred to as packagecarrier 55. At the under side of the package carrier 55, at the positionwhere the elevated portion 22 of the carrier 20 has been, a through-likerecess 47 has been formed, wherein the covering member 40 is present atthe bottom of the recess 47. Furthermore, as a result of the removal ofthe carrier 20, the holes 41 of the covering member 40 are open.

In a fifth step of the process of manufacturing the second package,which is illustrated by FIG. 3 e, a MEMS microphone 60 or anothersuitable microelectronic element is placed in the recess 47 which isarranged in the under side of the body member 45. Furthermore, the MEMSmicrophone 60 is connected to the electrically conductive pattern 30that is present at the under side of the body member 45.

In a sixth step of the process of manufacturing the second package,which is illustrated by FIG. 3 f, the recess 47 containing the MEMSmicrophone 60 is closed by filling the recess 47 with a suitablematerial such as epoxy resin. In the process, the MEMS microphone 60gets encapsulated in a filler body 65 which is formed in this way. Thisstep of closing the recess 47 is the final step of the formation of thesecond package 2. In case the package 2 is manufactured as part of anarray 50 of packages 2, and has not been separated from the otherpackages 2 yet, a process of dicing the array is performed.

By carrying out the manufacturing method as described above, a compactand robust package 2 is realized, in which the MEMS microphone 60 andthe processor chip 61 are protected from damage. Nevertheless, the MEMSmicrophone 60 may be reached by sound waves, through the holes 41 in thecovering member 40. Furthermore, the electric circuit containing theelectrically conductive pattern 30, the MEMS microphone 60 and theprocessor chip 61 is easily connectable to another electronic device,through the tracks 32 and connection pads 31 of the pattern 30, whichare present at the under side of the body member 45, while extendingoutside of the recess 47.

FIGS. 4 a to 4 i illustrate subsequent steps of a process ofmanufacturing a diagnostic device according to a second preferredembodiment of the present invention. In the following, the manufacturingprocess will be described for one diagnostic device. Nevertheless, thediagnostic device may be manufactured as part of an array of devices.

In each of FIGS. 4 c to 4 h, both a perspective view of an under side ofthe diagnostic device in the process of formation and a perspective viewof an upper side of the diagnostic device in the process of formationare shown. Furthermore, in FIG. 4 i, both a perspective view of an underside of a microfluidic plate of the diagnostic device and a perspectiveview of an upper side of this microfluidic plate are shown.

In a first step of the process of manufacturing the diagnostic device,which is illustrated by FIG. 4 a, a sacrificial carrier 20 is provided.The carrier 20 comprises a sheet of material, for example copper. At acarrying surface 24, the carrier 20 is provided with a pattern 30 ofelectrically conductive connection pads 31 and electrically conductivetracks 32.

The carrier 20 is bent in such a way that two portions 22, 23 which arelocated at a different level are obtained. In particular, after bendingof the carrier 20 has taken place, an elevated portion 22 and a recessedportion 23 of the carrying surface 24 are discernible. At the elevatedportion 22 of the carrying surface 24 of the carrier 20, a coveringmember 40 is arranged in the form of a thin layer of electricallyinsulating material having a hole 41.

In a second step of the process of manufacturing the diagnostic device,which is illustrated by FIG. 4 b, a processor chip 61 or anothersuitable microelectronic element is positioned on the recessed portion23 of the carrying surface 24, wherein electric connections between theprocessor chip 61 and both the electrically conductive connection pads31 and the electrically conductive tracks 32 of the pattern 30 arerealized.

In a third step of the process of manufacturing the diagnostic device,which is illustrated by FIG. 4 c, the carrier 20 and the components 30,40, 61 arranged on its carrying surface 24 are overmolded with asuitable material, on the basis of which a body member 45 is formed onthe carrier 20, at the side of the carrying surface 24. In the process,the processor chip 61 gets encapsulated in the body member 45.Furthermore, in the process, a trough-like recess 46 is formed in thebody member 45, wherein a top side of the covering member 40 is locatedat a bottom of the recess 46. The body member 45 may be created andshaped by positioning the carrier 20 and the components 30, 40, 61arranged on its carrying surface 24 in a mould and introducing materialfor forming the body member 45 in this mould, in a manner which issimilar to the manner which has been already been discussed in respectof the manufacturing process of the first package 1.

In a fourth step of the process of manufacturing the diagnostic device,which is illustrated by FIG. 4 d, the carrier 20 is removed by chemicaletching, peeling, or another suitable technique. The product that isobtained as the result of this step is also referred to as packagecarrier 55. At the under side of the body member 45, at the positionwhere the elevated portion 22 of the carrier 20 has been, a through-likerecess 47 has been formed, wherein the covering member 40 is present ata bottom of the recess 47. Furthermore, as a result of the removal ofthe carrier 20, the hole 41 of the covering member 40 is open.

In a fifth step of the process of manufacturing the diagnostic device,which is illustrated by FIG. 4 e, a sensor die 60 or another suitablemicroelectronic element is placed in the recess 47 which is arranged inthe under side of the body member 45. Furthermore, the sensor die 60 isconnected to the electrically conductive pattern 30 that is present atthe under side of the body member 45.

In a sixth step of the process of manufacturing the diagnostic device,which is illustrated by FIG. 4 f, the recess 47 containing the sensordie 60 is closed by filling the recess 47 with a suitable material suchas epoxy resin. In the process, the sensor die 60 gets encapsulated in afiller body 65 which is formed in this way.

In a seventh step of the process of manufacturing the diagnostic device,which is illustrated by FIG. 4 g, reagents 81, 82 are applied to thebottom of the open recess 46 that is located at an upper side of thebody member 45.

In an eighth step of the process of manufacturing the diagnostic device,which is illustrated by FIG. 4 h, a microfluidic plate 72, which has apattern 73 of channels for conducting a fluid, which is present at oneside of the plate 72, is placed in the recess 46, such that the side ofthe plate 72 having the pattern 73 of channels faces the bottom of therecess 46. The microfluidic plate 72 is shown in FIG. 4 i. In the shownexample, the microfluidic plate 72 is adapted to leaving one of thereagents 81, 82 uncovered. For the purpose of putting fluid into contactwith another of the reagents 81, 82, the microfluidic plate 72 comprisesa channel 74 which is shaped like a circular recess. For the purpose ofsupplying the fluid to the sensor die 60, through the hole 41 in thecovering member 40, the microfluidic plate 72 comprises a supply channel75. Furthermore, for the purpose of discharging the fluid from the hole41, the microfluidic plate 72 comprises two discharge channels 76.

Within the scope of the present invention, the microfluidic plate 72 mayhave any suitable shape and comprise any suitable pattern 73 ofchannels, wherein it is important that the design of the microfluidicplate 72 is adapted to conducting fluid over the reagents 81, 82 and asensitive surface of the sensor die 60, through the hole 41 in thecovering member 40. Furthermore, the microfluidic plate 72 may bemanufactured from any suitable material. In this respect, an example ofa suitable material is plastic.

In the diagnostic device 6 which is obtained as a result of themanufacturing process as described on the basis of FIGS. 4 a to 4 i, thesensor die 60 is safely embedded in the filler body 65, and theprocessor chip 61 is safely embedded in the body member 45. The recess47 in which the sensor die 60 is located is obtained in an easy manner,namely by bending a sacrificial carrier 20 in such a way that portions22, 23 which are located at a different level obtained. At the locationof an elevated portion 22 which is formed in the carrier 20 in this way,the recess 47 is automatically obtained when the carrier 20 is coveredby material for the purpose of forming the body member 45.

An electric circuit of the diagnostic device 6, which comprises thesensor die 60 and the processor chip 61, is connectable to a read-outunit or another electronic device by means of connection pads 31 whichlay exposed on the under side of the device 6.

An advantageous feature of the diagnostic device 6 is constituted by thefact that the covering member 40 may be relatively thin, so that thesensitive surface of the sensor die 60 may almost be at the same levelas the bottom of the recess 46. As a consequence, it is ensured that thediagnostic device 6 is capable of yielding accurate results during itsoperation, as the fluid to be examined is passed over the sensitivesurface of the sensor die 60 in a controlled manner, wherein the flow ofthe fluid is practically not disturbed at the location of the hole 41.

Advantageously, longitudinal axes 461, 471 of the recesses 46, 47 whichare arranged in the body member 45 of the diagnostic device 6 extend indirections which are at right angles with respect to each other, so thatan area where the device 6 only comprises the relatively thin coveringmember 40 is as small as possible. In this way, the diagnostic device 6may still be as robust as possible. It is noted that the directions inwhich the longitudinal axes 461, 471 as mentioned are extending do notnecessarily need to be at right angles with respect to each other forthe purpose of having a robust device 6. In general, this effect isobtained when the directions in which these longitudinal axes 461, 471are extending differ from each other.

The packages 1, 2 and the diagnostic devices 5, 6 as described in theforegoing are only a few of the numerous possibilities existing withinthe scope of the present invention. The disclosed packages 1, 2 anddiagnostic devices 5, 6 are as small as possible, and do not compriseunnecessary space.

The manufacturing processes of the packages 1, 2 and the diagnosticdevices 5, 6 do not involve any complicated steps, and may be performedat low cost. Also, the applied materials do not need to be expensive.

Within the scope of the present invention, the number of microelectronicelements 60, 61 enclosed by the packages 1, 2 and the diagnostic devices5, 6 may be chosen freely, in spite of the fact that in the foregoing,only examples of the application of just one microelectronic element 60and examples of the application of two microelectronic elements 60, 61have been described.

It will be clear to a person skilled in the art that the scope of thepresent invention is not limited to the examples discussed in theforegoing, but that several amendments and modifications thereof arepossible without deviating from the scope of the present invention asdefined in the attached claims.

In the foregoing, a method has been described for manufacturing apackage 1, 2 enclosing at least one microelectronic element 60 such as asensor die and having electrically conductive connection pads 31 forelectric connection of the package 1, 2 to another device. Inparticular, this method comprises the steps of providing a sacrificialcarrier 20; applying an electrically conductive pattern 30 to one sideof the carrier 20; bending the carrier 20 in order to create a shape ofthe carrier 20 in which the carrier 20 has an elevated portion 22 and atleast one recessed portion 23; forming a body member 45 on the carrier20 at the side where the electrically conductive pattern 30 is present;removing the sacrificial carrier 20; and placing a microelectronicelement 60 in a recess 47 which has been created in the body member 45at the position where the elevated portion 22 of the carrier 20 hasbeen, and connecting the microelectronic element 60 to the electricallyconductive pattern 30. Furthermore, a hole 41 is arranged in the package1, 2 for providing access to a sensitive surface of the microelectronicelement 60, and another recess 46 is formed for the purpose of at leastpartially receiving a member 70, 72 for conducting fluid toward the hole41.

1.-11. (canceled)
 12. Package carrier, comprising: a body member havinga recess for accommodating a microelectronic element; and a pattern ofelectrically conductive connection pads and electrically conductivetracks arranged at one side of the body member such that at least one ofthe electrically conductive connection pads is present in the recess;wherein the body member has at least one hole and the recess extends tothe hole.
 13. The package carrier according to claim 12, furthercomprising a microelectronic element arranged in the recess of the bodymember and connected to at least one of the electrically conductiveconnection pads.
 14. Package carrier according to claims 12, furthercomprising a covering member applied to the body member and having theat least one hole of the body member.
 15. Package carrier according toclaim 13, wherein the recess with the microelectronic element is filledwith an encapsulant.
 16. Package carrier according to claim 12, whereinthe body member has another recess arranged at another side of the bodymember than the side where the recess and the electrically conductivepattern are present, and wherein the at least one hole of the bodymember is present at a bottom of the recess.
 17. Package carrieraccording to claim 16, wherein longitudinal axes of the recesses whichare arranged at different sides of the body member extend in differentdirections. 18.-22. (canceled)